package laugh.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;

import com.sun.image.codec.jpeg.ImageFormatException;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

/**
 * 
*    
* 项目名称：LaughFactory   
* 类名称：ValidateCodeUtil   
* 类描述：   
* 创建人：wizard   
* 创建时间：2012-3-29 上午10:28:08   
* 修改人：wizard   
* 修改时间：2012-3-29 上午10:28:08   
* 修改备注：   
* @version 0.9
*
 */
public class ValidateCodeUtil {

    // 用数组CHARs数组来保存所有能够产生的字符
    public static final char[] CHARs = { '2', '3', '4', '5', '6', '7', '8',
            '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M',
            'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
    public static Random random = new Random();

    // 下面是产生六个随机数
    public static String getRandomString() {
        StringBuffer buffer = new StringBuffer();
        for (int i = 0; i < 6; i++) {
            buffer.append(CHARs[random.nextInt(CHARs.length)]);
        }
        return buffer.toString();
    }

    // 用三个随机数来分别产生ＲＧＢ的数值
    public static Color getRandomColor() {
        return new Color(random.nextInt(255), random.nextInt(255),
                random.nextInt(255));
    }

    // 产生反色的颜色
    public static Color getgetReverseColor(Color c) {
        return new Color(255 - c.getRed(), 255 - c.getGreen(),
                255 - c.getBlue());

    }

    public static void doIt(HttpServletRequest request, ServletOutputStream out) {
        String randomString = getRandomString();// 获取随机数
        System.out.println("randomString:" + randomString);
        request.getSession(true).setAttribute("randomString", randomString);
        // 生成的验证码图像的大小
        int width = 100;
        int height = 30;
        Color color = getRandomColor();
        Color reverse = getgetReverseColor(color);
        BufferedImage bi = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_RGB);
        Graphics2D g = bi.createGraphics();
        g.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 16));
        g.setColor(color);
        g.fillRect(0, 0, width, height);
        g.setColor(reverse);
        g.drawString(randomString, 18, 20);
        // 用来产生污点来防止被破解
        for (int i = 0, n = random.nextInt(100); i < n; i++) {
            g.drawRect(random.nextInt(width), random.nextInt(height), 1, 1);

        }
        JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
        try {
            encoder.encode(bi);
        } catch (ImageFormatException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}
